This is a note to let you know that I've just added the patch titled ip_tunnel: fix kernel panic with icmp_dest_unreach to the 3.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ip_tunnel-fix-kernel-panic-with-icmp_dest_unreach.patch and it can be found in the queue-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b7722eeecedff96f5e4adb8cb25cd03ef5c364d4 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Fri, 24 May 2013 05:49:58 +0000 Subject: ip_tunnel: fix kernel panic with icmp_dest_unreach From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit a622260254ee481747cceaaa8609985b29a31565 ] Daniel Petre reported crashes in icmp_dst_unreach() with following call graph: Daniel found a similar problem mentioned in http://lkml.indiana.edu/hypermail/linux/kernel/1007.0/00961.html And indeed this is the root cause : skb->cb[] contains data fooling IP stack. We must clear IPCB in ip_tunnel_xmit() sooner in case dst_link_failure() is called. Or else skb->cb[] might contain garbage from GSO segmentation layer. A similar fix was tested on linux-3.9, but gre code was refactored in linux-3.10. I'll send patches for stable kernels as well. Many thanks to Daniel for providing reports, patches and testing ! Reported-by: Daniel Petre <daniel.petre@xxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/ip_gre.c | 2 +- net/ipv4/ipip.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -722,6 +722,7 @@ static netdev_tx_t ipgre_tunnel_xmit(str tiph = &tunnel->parms.iph; } + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); if ((dst = tiph->daddr) == 0) { /* NBMA tunnel */ @@ -865,7 +866,6 @@ static netdev_tx_t ipgre_tunnel_xmit(str skb_reset_transport_header(skb); skb_push(skb, gre_hlen); skb_reset_network_header(skb); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); skb_dst_drop(skb); --- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -448,6 +448,7 @@ static netdev_tx_t ipip_tunnel_xmit(stru if (tos & 1) tos = old_iph->tos; + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); if (!dst) { /* NBMA tunnel */ if ((rt = skb_rtable(skb)) == NULL) { @@ -530,7 +531,6 @@ static netdev_tx_t ipip_tunnel_xmit(stru skb->transport_header = skb->network_header; skb_push(skb, sizeof(struct iphdr)); skb_reset_network_header(skb); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); skb_dst_drop(skb); Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-3.4/ipv6-fix-possible-crashes-in-ip6_cork_release.patch queue-3.4/tcp-xps-fix-reordering-issues.patch queue-3.4/ip_tunnel-fix-kernel-panic-with-icmp_dest_unreach.patch queue-3.4/tcp-fix-tcp_md5_hash_skb_data.patch queue-3.4/net-force-a-reload-of-first-item-in-hlist_nulls_for_each_entry_rcu.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html